# Making a Sinatra app respect UTF-8:
#
# 1.  At the top of your app file, set $KCODE to 'u'.
#     This ensures your regexps are in UTF-8 mode by default,
#     and #inspect will output UTF-8 chracters correctly.
#     This option is on by default as of Ruby 1.9.
#     For more information on the $KCODE setting, see:
#     http://blog.grayproductions.net/articles/the_kcode_variable_and_jcode_library
$KCODE = 'u' if RUBY_VERSION < '1.9'

# 2.  Set content-type with charset=utf-8 param (not the default setting.)
#     This ensures the browser will render utf-8 characters correctly.
#     A before filter is a good place to do this:
before do
  content_type :html, 'charset' => 'utf-8'
end

UTF-8 encoding in Sinatra

Ruby